Separation and polishing of rice grains



1969 TOSHIHIKO SATAKE 3,472,660

SEPARATION AND POLI$HING OF RICE GRAINS Filed Jan. 12, 1966 United States Patent Oihce 3,472,660 Patented Oct. 14, 1969 Int. Cl. A231 1/10 US. Cl. 99-80 1 Claim ABSTRACT OF THE DISCLOSURE Producing a high yield of polished rice by hulling a mixture of normal grains and unripe grains, separating the hulled unripe grains from the hulled normal grains and polishing each type of grain in a polishing machine adapted to that type of grain.

The present invention relates to a process of refining rice grains, particularly to a process of treating the rice grains including separating and polishing the rice grains.

Among harvested rice grains, some unripe grains are found. In general, harvested grains first are hulled by a hulling machine. The grains delivered from the hulling machine include grains which have not been hulled by the hulling machine. Therefore, the grains delivered from the hulling machine must be treated by a separator separating the unhulled grains from the grains. However, the known separators can not separate the unripe grains from the normal grains. Therefore, the mixture of the hulled unripe grains and the hulled ripe normal grains are fed to a polishing machine. The polishing machine is adapted to polish the ripe normal hulled grains but not to polish the unripe grains.

During the polishing action in the polishing machine, the unripe hulled grains are crushed into pulverized particles. Hitherto, as the unripe grains are pulverized in the polishing treatment, the yield of the polished grains is low.

An object of the present invention is to provide a process of treating rice grains with a high efiiciency and a high yield.

In the present invention, grains treated in a hulling machine are further treated as undermentioned. The grain mixture from said hulling machine is separated into a group of unhulled grains, a group of hulled unripe grains, a group of hulled ripe normal grains and a group consisting of hulled ripe normal grains and unhulled grains by an oscillating separator. The group of hulled normal grains is supplied to a polishing machine. Since the group of hulled unripe grains includes a small amount of hulled ripe normal grains, this group is supplied to a line separator and separated into new two groups of hulled ripe normal grains and of hulled unripe grains. The separated hulled ripe normal grains are added to the group of hulled normal grains from the oscillating separator and the resultant mixture is charged to the polishing arrangement for the exclusive use for polishing the normal grains. The hulled unripe grains are charged to a polishing arrangement for the exclusive use for polishing the unripe grains.

Therefore, in the present invention the hulled ripe normal grains discharged from the separator are directly supplied to the polishing machines. Grains to be supplied to the line-separator consist of the hulled unripe grains and a small amount of the hulled ripe normal grains mixed with said unripe grains. Therefore, the lineseparator does not need a large capacity. A large amount of the primary normal grains is supplied directly to the polishing machines and an amount of the normal grains from the line-separator is added to said primary grains from the oscillating separator, so that the efiiciency of treating may be high. Further, in the present invention, the hulled unripe grains are supplied to the polishing machine for the exclusive use for said unripe grains, so that said unripe grains are polished without being pulverized into particles. Therefore, the yield of the polished grains can be of a high degree.

Another object of the present invention is to provide a process for treating rice grains comprising supplying the mixture consisting of hulled grains and hulled normal grains to an oscillating separator, supplying a stream of hulled normal grains discharged from said oscillating separator to a polishing arrangement for the exclusive use for said hulled normal grains, supplying a stream of hulled unripe grains including a small amount of the hulled normal grains discharged from said oscillating separator to a line-separator, additionally adding a stream of the hulled normal grains discharged from said lineseparator to said stream towards said polishing machine for the normal grains, and supplying a stream of the hulled unripe grains discharged from said line-separator to a polishing arrangement for the exclusive use for the unripe grains.

Other objects and the advantages of the present invention will be understood from the following description referring to the accompanying drawing, in which;

The sole figure shows a diagrammatic arrangement for treating the hulled rice grains according to the present invention.

In the first place, rice grains which have been harvested are subjected to a hulling operation in hulling machine 1. The unhulled grains are fed into the hulling machine 1 through a hopper 2 disposed at the top portion of said hulling machine 1. In this hulling machine 1, hull particles removed from the unhulled grains are blown out by a blower 3 connected to said machine 1 through a duct 4. A mixture consisting of hulled normal grains, hulled unripe grains and unhulled grains is discharged from the hulling machine 1 through a trough 5 to an inlet port 6 of a pneumatic lift 7.

The top portion of the pneumatic lift 7 is connected to a receiving hopper 8 through a duct 9. The mixture from the hulling machine is supplied onto an oscillating plate 10 of an oscillating separator 11 and is separated in known manner into four streams consisting of the hulled unripe grains, the hulled normal grains, a mixture consisting of the hulled normal grains and the unhulled grains. The oscillating plate 10 is disposed obliquely in the longitudinal and lateral directions and is oscillated in the lateral direction.

In said oscillating separator 11, four discharge outlet ports 12, 13, 14 and 15 are disposed at the lower end portion. From the outlet port 12, the unripe grains including a small amount of the hulled normal grains are discharged. From the outlet portion 13, the normal grains are discharged. From the outlet port 14, the unhulled grains including a small amount of the hulled normal grains are discharged. From the outlet port 15, the unhulled grains are discharged. The stream of the unhulled grains discharged from the outlet port 15 is supplied to the pneumatic lift 16 of the hulling machine 1 and treated again in said hulling machine 1. The stream of the hulled normal grains including a small amount of the unhulled grains from the outlet port 14 is supplied to the pneumatic lift 7 and is treated again by the oscillating separator. The stream of the hulled normal grains from the outlet port 13 is supplied to a polishing arrangement A comprising three polishing machines 20, 21 and 22 through a pneumatic lift 19. A duct 18 connects the outlet port 13 to a receiving opening 17 of the pneumatic lift 19. The stream of the unripe grains including some amount of the normal grains is supplied to a pneumatic lift '23 through a receiving opening 35. The top end of the pneumatic lift 23 is connected to a receiving hopper 24 of a line-separator 25 through a duct 26. Therefore, the grains supplied to the opening 35 is fed to the line-separator 25. The unripe grains including some amount of the normal grains run down on the lines disposed in parallel, the unripe grains drop down between the lines and the normal grains, which are larger than the unripe grains, and the normal grain is supplied into the receiving opening 17 of the pneumatic lift 19 so as to flow together with the stream of the hulled normal grains from the outlet port 13.

The hulled unripe grains are discharged from a discharge opening 27 and are fed to a receiving opening 28 of a pneumatic lift 29 through a duct 30. The top of the pneumatic lift 29 is connected to a receiving hopper 31 of a polishing arrangement B comprising three polishing machines 32, 33 and 34.

In the arrangement A, the polishing machines 20 and 21 are of a known grinder type and the polishing machine 22 is of a known blower type. These machines are disposed in series.

In the arrangement B, the polishing machine 32 is of a grinder type the same as the machines 20 and 21 and the polishing machines 33 and 34 are of a blower type the same as the polishing machine 22. These machines 32, 33 and 34 are disposed in series.

In the present invention, the hulled unripe grains are treated by the polishing arrangement for the exclusive use for said unripe grains, so that the polishing treatment may be carried out with the pulverization of the grains.

What I claim is:

l. A continuous method of treating rice grains to produce a high yield of polished rice comprising hulling rice to produce a mixture consisting of unhulled grains, hulled unripe grains and hulled normal grains, subjecting said mixture to an oscillating separator, supplying a stream of hulled normal grains discharged from said separator to a polishing machine for the exclusive use for said hulled grains, supplying a stream of hulled unripe grains including a small amount of hulled normal grains discharged from said oscillating separator to a lineseparator, adding the hulled normal grains discharged from said line-separator to the hulled normal grain stream from said oscillating separator, supplying said hulled unripe grains discharged from said line-separator to a polishing machine for the exclusive use for said hulled unripe grains, returning a stream of unhulled grains discharged from said oscillating separator to a hulling station for hulling treatment and returning a stream consisting of the unhulled and hulled grains discharged from said oscillating separator to said oscillating separator to repeat the separation cycle.

References Cited UNITED STATES PATENTS 807,990 12/1905 Ball 146221.5

RAYMOND N. JONES, Primary Examiner JAMES R. HOFFMAN, Assistant Examiner US. Cl. X.R. 146-2215, 280 

